Exogenous Application Of Brassinosteroids Research Articles

Exogenous brassinosteroids application in purple passion fruit plants grafted onto a sweet calabash passion fruit rootstock and under water stress

The purple passion fruit is a fruit species of great importance in high Andean areas, but it can be affected by water deficit conditions. The objective of this study was to determine the effect of the application of brassinosteroids on purple passion fruit grafted on Passiflora maliformis and under water deficit. The plants were subjected to different levels of irrigation (100%, 50% and 25% of the evaporated amount) and some were applied with brassinosteroid analogue (DI-31). The fresh and dry mass of the aerial part and the root, leaf area, height of the aerial part, electrolyte loss, relative chlorophyll content, stomatal conductance, and maximum PSII quantum efficiency (Fv/Fm) were determined. It was observed that water stress negatively affected the height, leaf area, and fresh and dry masses of the plants at 84 days after treatment (dat). On the other hand, the results indicate a positive effect of the brassinosteroids on the height, leaf area, and fresh and dry masses of the plants at the different levels of irrigation at 84 dat. An effect of water stress or the exogenous application of brassinosteroids on electrolyte loss was not detected, but these factors did affect Fv/Fm at 28 dat. These results are important for the formulation of integrated management plans for the cultivation of Passiflora edulis f. edulis Sims in a climate change scenario.

Brassinosteroids affect wood development and properties of Fraxinus mandshurica.

Xylem development plays a crucial role in wood formation in woody plants. In recent years, there has been growing attention towards the impact of brassinosteroids (BRs) on this xylem development. In the present study, we evaluated the dynamic variation of xylem development in Fraxinus mandshurica (female parent, M8) and a novel interspecific hybrid F. mandshurica × Fraxinus sogdiana (1601) from May to August 2020. We obtained RNA-Seq transcriptomes of three tissue types (xylem, phloem, and leaf) to identify the differences in xylem-differentially expressed genes (X-DEGs) and xylem-specifically expressed genes (X-SEGs) in M8 and 1601 variants. We then further evaluated these genes via weighted gene co-expression network analysis (WGCNA) alongside overexpressing FmCPD, a BR biosynthesis enzyme gene, in transient transgenic F. mandshurica. Our results indicated that the xylem development cycle of 1601 was extended by 2 weeks compared to that of M8. In addition, during the later wood development stages (secondary wall thickening) of 1601, an increased cellulose content (14%) and a reduced lignin content (11%) was observed. Furthermore, vessel length and width increased by 67% and 37%, respectively, in 1601 compared with those of M8. A total of 4589 X-DEGs were identified, including enzymes related to phenylpropane metabolism, galactose metabolism, BR synthesis, and signal transduction pathways. WGCNA identified hub X-SEGs involved in cellulose synthesis and BR signaling in the 1601 wood formation-related module (CESA8, COR1, C3H14, and C3H15); in contrast, genes involved in phenylpropane metabolism were significantly enriched in the M8 wood formation-related module (CCoAOMT and CCR). Moreover, overexpression of FmCPD in transient transgenic F. mandshurica affected the expression of genes associated with lignin and cellulose biosynthesis signal transduction. Finally, BR content was determined to be approximately 20% lower in the M8 xylem than in the 1601 xylem, and the exogenous application of BRs (24-epi brassinolide) significantly increased the number of xylem cell layers and altered the composition of the secondary cell walls in F. mandshurica. Our findings suggest that BR biosynthesis and signaling play a critical role in the differing wood development and properties observed between M8 and 1601 F. mandshurica.

Brassinosteroids alleviate nanoplastic toxicity in edible plants by activating antioxidant defense systems and suppressing nanoplastic uptake

As emerging pollutants of global concern, absorbed nanoplastics might have negative impacts on plant development and nutrient uptake, thereby decreasing yields. If nanoplastics are transferred to the edible parts of plants, they may pose a threat to human health when large quantities are ingested. While nanoplastic-induced phytotoxicity is attracting increasing attention, little is known about how to inhibit nanoplastic accumulation in plants and reduce the subsequent adverse effects. Here we investigated the absorption and accumulation of polystyrene nanoplastics (PS-NPs) in different plant species and the role of brassinosteroids in alleviating PS-NP toxicity. Brassinosteroids inhibited accumulation of PS-NPs in tomato fruit and reversed PS-NP-induced phytotoxicity to promote plant growth and increase fresh weight and plant height. Brassinosteroids also reversed the induction of aquaporin-related genes by PS-NPs including TIP2-1, TIP2-2, PIP2-6, PIP2-8, PIP2-9, SIP2-1, and NIP1-2, providing a potential stress mechanism by which PS-NPs accumulate in the edible parts and targets for inhibition. In transcriptomic analyses, brassinosteroids enhanced fatty acid and amino acid metabolism and synthesis. In conclusion, exogenous application of 50 nM brassinosteroids alleviated the adverse effects of PS-NPs on plants, and exogenous application of brassinosteroids might be an effective means to minimize PS-NP-induced phytotoxicity.

24-Epibrassinolide and 2,6-Dichlorobenzonitrile Promoted Celery Petioles and Hypocotyl Elongation by Altering Cellulose Accumulation and Cell Length

BRs (brassinosteroids), an endogenous hormone in plants, regulate cellulose accumulation, cell elongation and plant growth. Propiconazole (PCZ) is an effective inhibitor of BR biosynthesis. DCB (2,6-Dichlorobenzonitrile) can inhibit the synthesis of cellulose and affects the chemical composition of cell walls. Celery is one important leafy vegetable of the Apiaceae family with rich dietary fiber (including cellulose). The petioles length, leaf blades number and cellulose content determine the yield and quality of celery. The family members of AgCESAs are related to cellulose biosynthesis in higher plants. To investigate the effects of BRs, PCZ and DCB on the growth of celery, celery cv. ‘Jinnan Shiqin’ plants were treated with 24-epibrassinolide (24-EBL, most active form of BRs), PCZ and DCB, respectively. The results showed that exogenous application of BRs up-regulated the expression of AgCESAs genes and accumulated more cellulose in celery. The length of petioles and number of leaf blades in celery plants applied with exogenous BRs (1.24 × 10−6 mol/L 24-EBL) were increased 2.16 and 1.37 times of that in the control. The addition of PCZ inhibited the effects of exogenous BRs application. The lengths of hypocotyl and hypocotyl cells of celery plants treated with BRs were longer than that of the control. Under DCB treatments, the expression levels of AgCESAs genes in celery petioles and leaf blades were down-regulated compared with the control, and the celery plants showed decreased cellulose content, shorter petiole length and fewer leaf blades. The length of hypocotyl and hypocotyl cells of celery treated with DCB were shorter than that of the control. This study provided a reference for the functions of BRs and DCB on the growth and development of celery.

Do brassinosteroids alleviate water stress in seedlings of Handroanthus serratifolius?

AbstractLimited water availability in reforestation areas can compromise plant growth and development, especially for plants at early stages. In this context, the exogenous application of growth regulators, such as brassinosteroids (BRs), can be used to mitigate the negative effects of water restriction. The aim of this study was to evaluate the effect of the application of BRs (90% brassinolide + a brassinosteroid) on initial growth, gas exchange, leaf water potential and leaf anatomy in yellow Ipê (Handroanthus serratifolius), under water restriction conditions. Throughout the experimental period, plants were maintained in two different water regimes: WR1—plants maintained at 100% of the pot capacity; WR2—plants rehydrated with 50% of the evapotranspiration from the previous day. BRs were applied on three occasions during the experimental period, in five concentrations: C1, 0 g/L (application of distilled water); C2, 0.25 g/L; C3, 0.5 g/L; C4, 0.75 g/L; and C5, 1.00 g/L. The dry mass, root:shoot ratio, water status and leaf anatomy traits were evaluated at the end of the experimental period and were analysed in two‐level factorial scheme (2WR × 5BRs concentrations). The plant height, number of leaves, gas exchange and leaf chlorophyll content were evaluated four times during the experimental period and were analysed in a split‐split‐plot design (two WR × five BRs concentrations × four evaluation times). The differences between the means were evaluated by analysis of variance (ANOVA). Pairs of means were separated using the standard error of the difference between the means (SED) and the Fisher's protected least significant difference test (LSD) at p < .05. In addition, all variables were subjected to regression analysis, being the variables evaluated over time, analysed through a two‐stage modelling approach. The results obtained indicate that the water deficit led to reductions in growth and gas exchange parameters, regardless of the exogenous application of the regulator; therefore, higher concentrations (C4 and C5) were the most harmful for the maintenance of metabolic and photosynthetic activity. The exogenous application of BRs in H. serratifolius plants attenuated the effects of water limitation on the leaf water potential, but was not able to mitigate for the negative effects in growth, gas exchange and leaf anatomy.

Brassinosteroids suppress ethylene-induced fruitlet abscission through LcBZR1/2-mediated transcriptional repression of LcACS1/4 and LcACO2/3 in litchi

Abscission in plants is tightly controlled by multiple phytohormones and the expression of various genes. However, whether the plant hormone brassinosteroids (BRs) are involved in this process is largely unknown. Here, we found that exogenous application of BRs reduced the ethylene-induced fruitlet abscission of litchi due to lower ethylene (ET) production and suppressed the expression of the ethylene biosynthetic genes LcACS1/4 and LcACO2/3 in the fruitlet abscission zone (FAZ). Two genes that encode the BR core signaling components brassinazole resistant (BZR) proteins, namely, LcBZR1 and LcBZR2, were characterized. LcBZR1/2 were localized to the nucleus and acted as transcription repressors. Interestingly, the LcBZR1/2 transcript levels were not changed during ET-induced fruitlet abscission, while their expression levels were significantly increased after BR application. Moreover, gel shift and transient expression assays indicated that LcBZR1/2 could suppress the transcription of LcACS1/4 and LcACO2/3 by specifically binding to their promoters. Importantly, ectopic expression of LcBZR1/2 in Arabidopsis significantly delayed floral organ abscission and suppressed ethylene biosynthesis. Collectively, our results suggest that BRs suppress ET-induced fruitlet abscission through LcBZR1/2-controlled expression of genes related to ethylene biosynthesis in litchi. In addition, similar results were observed in the Arabidopsis gain-of-function mutant bzr1-1D, which showed delayed floral organ abscission in parallel with lower expression of ACS/ACO genes and reduced ethylene production, suggesting that the mechanism of BZR-controlled organ abscission via regulation of ethylene biosynthesis might be conserved in Arabidopsis.

Regulation of sterol content and biosynthetic gene expression during flower opening and early fruit development in olive.

Phytosterols are lipophilic membrane components essential not only for diverse cellular functions but also are biosynthetic precursors of the plant hormone, brassinosteroid (BR). However, the interaction between phytosterol and BR during early fleshy-fruit growth remains largely uncharacterized. In olive, phytosterols are important lipids because they affect oil quality, but phytosterol composition during flowering and early fruit development has not been explored. Here, we first investigated the temporal changes in phytosterol composition, and biosynthetic gene expression that occurred during olive flower opening and early fruit growth. Next, we analyzed the interrelationship between phytosterol and BR, whose levels we manipulated through the application of exogenous BRs (24-epibrassinolide, EBR) or a BR biosynthesis inhibitor (brassinazole, Brz). In this report, the profiling of phytosterol measurement revealed that β-sitosterol is the most abundant in olive reproductive organs. Our data demonstrate that both OeCYP51 and OeSMT2 genes are upregulated during floral anthesis in good agreement with the rise in cholesterol and β-sitosterol contents in olive flower. By contrast, the OeCYP51 and OeSMT2 genes displayed different expression patterns during early olive-fruit development. Furthermore, our data show that exogenous EBR enhanced the early olive-fruit growth, as well as the OeSMT2 transcript and β-sitosterol levels, but decreased the OeCYP51 transcript, squalene, campesterol and cholesterol levels, whereas the Brz treatment exerted the opposite effect. Overall, our findings indicate an up-regulation of β-sitosterol biosynthesis by BR at the transcriptional level during early olive-fruit growth, providing a valuable tool to unravel the physiological function of SMT2 in future studies.

Genome-wide identification of SERK genes in apple and analyses of their role in stress responses and growth

BackgroundSomatic embryogenesis receptor-like kinases (SERKs) are leucine-rich repeat receptor-like kinases associated with various signaling pathways. These kinases have a relationship with stress signals, and they are also believed to be important for regulating plant growth. However, information about this protein family in apple is limited.ResultsTwelve apple SERK genes distributed across eight chromosomes were identified. These genes clustered into three distinct groups in a phylogenetic analysis. All of the encoded proteins contained typical SERK domains. The chromosomal locations, gene/protein structures, synteny, promoter sequences, protein–protein interactions, and physicochemical characteristics of MdSERK genes were analyzed. Bioinformatics analyses demonstrated that gene duplications have likely contributed to the expansion and evolution of SERK genes in the apple genome. Six homologs of SERK genes were identified between apple and Arabidopsis. Quantitative real-time PCR analyses revealed that the MdSERK genes showed different expression patterns in various tissues. Eight MdSERK genes were responsive to stress signals, such as methyl jasmonate, salicylic acid, abscisic acid, and salt (NaCl). The application of exogenous brassinosteroid and auxin increased the growth and endogenous hormone contents of Malus hupehensis seedlings. The expression levels of seven MdSERK genes were significantly upregulated by brassinosteroid and auxin. In addition, several MdSERK genes showed higher expression levels in standard trees of ‘Nagafu 2’ (CF)/CF than in dwarf trees of CF/‘Malling 9’ (M.9), and in CF than in the spur-type bud mutation “Yanfu 6” (YF).ConclusionThis study represents the first comprehensive investigation of the apple SERK gene family. These data indicate that apple SERKs may function in adaptation to adverse environmental conditions and may also play roles in controlling apple tree growth.

Modulation of sphingolipid long-chain base composition and gene expression during early olive-fruit development, and putative role of brassinosteroid

Sphingolipids are abundant membrane components and signalling molecules in various aspects of plant development. However, the role of sphingolipids in early fleshy-fruit growth has rarely been investigated. In this study, we first investigated the temporal changes in sphingolipid long-chain base (LCB) content, composition, and gene expression that occurred during flower opening and early fruit development in olive (Olea europaea L. cv Picual). Moreover, the interaction between sphingolipid and the plant hormone, brassinosteroid (BR), during the early fruit development was also explored. For this, BR levels were manipulated through the application of exogenous BRs (24-epibrassinolide, EBR) or a BR biosynthesis inhibitor (brassinazole, Brz) and their effects on early fruit development, sphingolipid LCB content, and gene expression were examined in olive fruit at 14 days post-anthesis (DPA). We here show that sphingolipid with C-4 hydroxylation and Δ8 desaturation with a preference for (E)-isomer formation are quantitatively the most important sphingolipids in olive reproductive organs. In this work, the total LCB amount significantly decreased at the anthesis stage, but olive sphingosine-1-phosphate lyase (OeSPL) gene was expressed exclusively in flower and upregulated during the anthesis, revealing an association with the d18:1(8E) accumulation. However, the LCB content increased in parallel with the upregulation of the expression of genes for key sphingolipid biosynthetic and LCB modification enzymes during early fruit development in olive. Likewise, we found that EBR exogenously applied to olive trees significantly stimulated the fruit growth rate whereas Brz inhibited fruit growth rate after 7 and 14 days of treatment. In addition, this inhibitory effect could be counteracted by the application of EBR. The promotion of early fruit growth was accompanied by the down-regulation of sphingolipid LCB content and gene expression in olive fruit, whereas Brz application raised levels of sphingolipid LCB content and gene expression in olive fruit after 7 and 14 days of treatment. Thus, our data indicate that endogenous sphingolipid LCB and gene-expression levels are intricately controlled during early fruit development and also suggest a possible link between BR, the sphingolipid content/gene expression, and early fruit development in olive.

Determination of the best 24-eBL application for the accumulation of antioxidant compounds in ‘Alphonse Lavallée’ grape cultivar by using fuzzy logic modelling

Brassinosteroids (BRs) are a class of polyhydroxysteroids that have been recognized as a “sixth class of plant hormones”. At present, 70 analogs have been identified, and among these, 24-epibrassinolide (24-eBL) is known to have an economic impact on plant metabolism, growth and productivity, and experience high stability under field conditions. Exogenous application of BRs are reported to confer resistance to plants against various abiotic stresses like heat, drought, heavy metals, salt and biotic stress like fungi and even viruses. Apart from resistance to biotic stresses, BRs also affect a broad spectrum of physiological responses like cell expansion, vascular differentiation, reproductive development, seed germination, flowering, fruit set and synthesis of antioxidant compounds in plants. In this study, the aim was to determine the best pre- harvest 24-eBL application for the accumulation of antioxidant compounds in 'Alphonse Lavallee' grape cultivar by using fuzzy logic modelling (FLM). For this aim, 24-eBL was applied to 9 years-old vines with 13 combinations including different application times that are our first input variables and 4 different concentrations (0.2, 0.4, 0.6 and 0.8 ppm) which are second input variables of our fuzzy logic model and control. Total phenolic content, total anthocyanin, trans-resveratrol, β-carotene and ascorbic acid were examined as antioxidant compounds in grapes. One, some or all of these can be used as output variables of our FLM to get the optimum result. By making the data continuous the model can be used for obtaining useful information about untested data so that the best solution, that is the best 24-eBL concentrations and application times, can be attained at some non-measured input variables for each antioxidant compound.

ROLE OF BRASSINOSTEROIDS IN MANGO FRUIT RIPENING

ISHS XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on Postharvest Technology in the Global Market ROLE OF BRASSINOSTEROIDS IN MANGO FRUIT RIPENING

Brassinosteroid Enhances Jasmonate‐Induced Anthocyanin Accumulation in Arabidopsis Seedlings

Jasmonate (JA) regulates plant development, mediates defense responses, and induces anthocyanin biosynthesis as well. Previously, we isolated the psc1 mutant that partially suppressed coi1 insensitivity to JA, and found that brassinosteroid (BR) was involved in JA signaling and negatively regulated JA inhibition of root growth in Arabidopsis. In this study it was shown that JA-induced anthocyanin accumulation was reduced in BR mutants or in wild type treated with brassinazole, an inhibitor of BR biosynthesis, whereas it was induced by an application of exogenous BR. It was also shown that the 'late' anthocyanin biosynthesis genes including DFR, LDOX, and UF3GT, were induced slightly by JA in the BR mutants relative to wild type. Furthermore, the expression level of JA-induced Myb/bHLH transcription factors such as PAP1, PAP2, and GL3, which are components of the WD-repeat/Myb/bHLH transcriptional complexes that mediate the 'late' anthocyanin biosynthesis genes, was lower in the BR mutants than that in wild type. These results suggested that BR affects JA-induced anthocyanin accumulation by regulating the 'late' anthocyanin biosynthesis genes and this regulation might be mediated by the WD-repeat/Myb/bHLH transcriptional complexes.

Postembryonic seedling lethality in the sterol-deficient Arabidopsis cyp51A2 mutant is partially mediated by the composite action of ethylene and reactive oxygen species.

Seedling-lethal phenotypes of Arabidopsis (Arabidopsis thaliana) mutants that are defective in early steps in the sterol biosynthetic pathway are not rescued by the exogenous application of brassinosteroids. The detailed molecular and physiological mechanisms of seedling lethality have yet to be understood. Thus, to elucidate the underlying mechanism of lethality, we analyzed transcriptome and proteome profiles of the cyp51A2 mutant that is defective in sterol 14alpha-demethylation. Results revealed that the expression levels of genes involved in ethylene biosynthesis/signaling and detoxification of reactive oxygen species (ROS) increased in the mutant compared with the wild type and, thereby, that the endogenous ethylene level also increased in the mutant. Consistently, the seedling-lethal phenotype of the cyp51A2 mutant was partly attenuated by the inhibition of ethylene biosynthesis or signaling. However, photosynthesis-related genes including Rubisco large subunit, chlorophyll a/b-binding protein, and components of photosystems were transcriptionally and/or translationally down-regulated in the mutant, accompanied by the transformation of chloroplasts into gerontoplasts and a reduction in both chlorophyll contents and photosynthetic activity. These characteristics observed in the cyp51A2 mutant resemble those of leaf senescence. Nitroblue tetrazolium staining data revealed that the mutant was under oxidative stress due to the accumulation of ROS, a key factor controlling both programmed cell death and ethylene production. Our results suggest that changes in membrane sterol contents and composition in the cyp51A2 mutant trigger the generation of ROS and ethylene and eventually induce premature seedling senescence.

AnArabidopsis short root and dwarfism mutant defines a novel locus that mediates both cell division and elongation

Arabidopsis leaf morphology is determined by the coordinated action of cell division and elongation. Of all the hormones that control leaf shape, the brassinosteroids (BRs) are active components in this process. BRs are a group of plant-originated steroidal compounds that induce growth along the long axes of organs. Here, we report the isolation and characterization of a novel mutant,short root and dwarfism (srd). Its dwarf phenotype includes round and curled leaves, reduced fertility, and short hypocotyls in the light and dark. Dwarfism in the aerial portions and a short-root morphology are not rescued by exogenous application of BRs, suggesting thatsrd is not impaired in BR metabolic pathways. Anatomical analysis revealed thatsrd roots are much shorter and thicker than the wild type due to additional layers of cortical cells. A lack of cell elongation but an increase in division results in these short but horizontally swollen roots. A double mutantsrd/bri1-5 also displays the short-root phenotype, implying thatsrd is epistatic tobri1. Cloning and further characterization ofSRD should provide additional information about its role in the determination of leaf shape and root elongation.

Ripened with Steroids

Fruits are divided into two classes: climacteric and nonclimacteric. By definition, nonclimacteric fruit ripens without the peak in ethylene and increase in respiration associated with ripening of climacteric fruits. Symons et al. provide evidence that brassinosteroids stimulate ripening of grape berries, specifically field-grown Cabernet Sauvignon. The abundance of castasterone (CS), a bioactive brassinosteroid, and its precursor increased during the period of berry ripening. Two enzymes involved in brassinosteroid biosynthesis (VvDWF1 and VvBR6OX1) and the brassinosteroid receptor (VvBRI1) were cloned from grape. Transcript analysis showed that VvDWF1 and VvBRI1 increased during berry ripening, whereas the abundance of VvBR6OX1 transcripts decreased. The decrease in VvBR6OX1 was consistent with negative feedback regulation by CS. This type of feedback by brassinosteroids has been reported in other species of plants. Application of exogenous brassinosteroid enhanced the rate of berry ripening, whereas application of an inhibitor brassinosteroid biosynthesis delayed berry ripening. Thus, brassinosteroids appear to serve a role in stimulating ripening of nonclimacteric fruits. Understanding nonclimacteric fruit ripening has important economic and agricultural implications, because several nonclimacteric fruits are grown for food or beverage production, including strawberry, grape, and citrus. G. M. Symons, C. Davies, Y. Shavrukov, I. B. Dry, J. B. Reid, M. R. Thomas, Grapes on steroids: Brassinosteroids are involved in grape berry ripening. Plant Physiol. 140 , 150-158 (2006). [Abstract] [Full Text]

Brassinosteroid의 대사공학

Sterols play two major roles in plants: a bulk component in biological membranes and precursors of plant steroid hormones. Physiological effects of plant steroids, brassinosteroids (BRs), include cell elongation, cell division, stress tolerance, and senescence acceleration. Arabidopsis mutants that carry genetic defects in BR biosynthesis or its signaling display characteristic phenotypes, such as short robust inflorescences, dark-green round leaves, and sterility. Currently there are more than 100 dwarf mutants representing 7 genetic loci in Arabidopsis. Mutants of 6 loci, dwf1/dim1/cbb1, cpd/dwf3, dwf4, dwf5, det2/dwf6, dwf7 are rescued by exogenous application of BRs, whereas bri1/dwf2 shares phenotypes with the above 6 loci but are resistant to BRs. These suggest that the 6 loci are defective in BR biosynthesis, and the one locus is in BR signaling. Biochemical analyses, such as intermediate feeding tests, examining the levels of endogenous BR, and molecular cloning of the genes revealed that dwf7, dwf5, and dwf1 are defective in the three consecutive steps of sterol biosynthesis, from episterol to campesterol via 5-dehydroepisterol. Similarly, det2/dwf6, dwf4, and cpd /dwf3 were shown to be blocked in D<TEX>$^4$</TEX>reduction, 22a-hydroxylation, and 23 a-hydroxylation, respectively. A signaling mutant bril/dwf2 carries mutations in a Leucine-rich repeat receptor kinase. Interestingly, the bri1 mutant was shown to accumulate significant amount of BRs, suggesting that signaling and biosynthesis are dynamically coupled in Arabidopsis. Thus it is likely that transgenic plants over-expressing the rate-limiting step enzyme DWF4 as well as blocking its use by BRIl could dramatically increase the biosynthetic yield of BRs. When applied industrially, BRs will boost new sector of plant biotechnology because of its potential use as a precursor of human steroid hormones, a novel lead compound for cholesterol-lowering effects, and a various application in plant protection.

Effect of brassinosteroids on growth, metabolite content and yield of arachis hypogaea

The effects of brassinolide and 24-epibrassinolide on growth, content of nucleic acids, soluble proteins, carbohydrate fractions and yield of groundnut (Arachis hypogaea L.) was studied. Brassinosteroids substantially increased the growth of the plant. Growth promotion by brassinosteroids was associated with enhanced levels of DNA, RNA, soluble proteins and various carbohydrate fractions. Exogenous application of brassinosteroids also resulted in enhanced yield and fat content.